I am very interested in how VMware networking works. I have scoured the VMware website and read their data sheets, this has given me some basic knowledge. I now have some questions.
Lets assume that we have a physical server running the VMware hypervisor. The physical server is running a Virtual Machine. The physical box has one physical NIC. The NIC is connected to a switch, as so is a desktop client.
Now, this is where my first question lies. The VM has an IP address: 192.168.1.1. How do desktop clients on the network communicate with this VM? So, the client pings 192.168.1.1. The ping packet is sent to the switch. The switch checks its MAC address table and sees that 192.168.1.1 is associated with the MAC address of the physical NIC. Correct?
I then assume that the ping packet is sent to the server's physical NIC, where the hypervisor routes the packet to the VM thats using 192.168.1.1?
Please could you give me a run down as to how VM networking works?
Best Answer
If you're talking about something like ESX or ESXi, your VM's are networking through a virtual switch in the physical server. So if your VM has an ip address of 192.168.1.2, and the VM server itself is 192.168.1.1, your ping from the client to 192.168.1.2 will go to the switch and from there to the server which then routes it (invisibly) to 192.168.1.2. As far as your client is aware, the virtual system is as real as the VM server.
Your switch just acts like there's multiple systems fed through a single port, much like it would if you had another switch connected to the switch.